Thomas b



'2 Sheets-Sheet 1.'

(NO Model.)

T. B. ROBERTS.

' SEWING MACHINE.

Patented June-27, 188Z.

PZT/VESSES." fii INVENTOR,

A TTORNE 141' N. PETERS. Phnlo-Lmwgnpher. Washington. n.0,

' UNITED STATES PATENT OFFICE.

THOMAS BLROBERTS, OF PITTSBURG, PA., ASSIGNOB OF TWO- THIRDS TO DAVID HUTOHISON AblD JOSEPH M. MOFFATT, OF SAME PLACE.

SEWING-MACHINE.

SPECIFICATION forming part of Letters Patent No. 260,240, dated June 2'7, 1882. Application filed January 13, 1882. (N model.)

To all whom it may concern: 7

Beit known that I, THOMAS B. RoBERtrs, of Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Sewing-Machines; and I do hereby declare that the following is a full, clear, and exact description of the invention, which will enable others skilled in the art to which it appertains to make and' ments in parts located under the platform.

Fig. 3 is a top view detached of the main shaft with my adjustable eccentric, the eccentric-lever being in section. Fig. 4 is a transverse section of part of the bed or platform, showing I my devices for taking up the wear 011 the journal of the shuttle-lever.

Thisinvention relates to the construction and combination of parts of sewing-machines of that class in which the shuttleis .driven by an oscillating lever driven by a lever connected to an eccentric on the main shaft, and the feed is accomplished by the double action of a reciprocating pitman driven by the Sl1l1l3l16-l6"91 and a pitman driven by the main shaft, and acting upon a feed-lever to give the rising and falling movement of the feed-plate.

The invention comprises a means of compensating for the wear of the main eccentric and its lever, a means of compensating for the wear on the journal of the shuttle-lever, and a means of regulating the feed'while accomplishiu g the rising and falling movement positively, and thereby dispensing with knockers and noiseless stops and cushions.

The invention consists in the construction and combination of parts substantially as hereinafter fully described and claimed.

In the drawings, I show a sewing-machine having the platform A, post 13, arm 0, head D, and shaft E, all of the usual construction in this class of machines.

it to the shaft E. 'Part-a (having integral therewith the pitman-eccentric a) has the collar c, and set-screw d, for attachment to the shaft E, and the part a has the beveled face I) on the side next the part a. The part a] has at a suitable location a stud or boss, 6, which fits accurately in a hole drilled in the part a at a corresponding point.

F is the eccentric-lever, whose upper end 1s formed as a fork, f f, the two prongs being parallel ontheir inner faces and V-shaped in cross-section, (see Fig. 3,) so as to fit in the angular recess formed by the faces I) b of the eccentrics a a on the main shaft. When the surfaces 1) b ff become worn and loose from use the set-screws d d are loosened and the two parts a a drawn together by turning the bolt 9, which bears against the outer face of the eccentric a and screws into the stud e of eccentric afluntil the wear is all taken up, af ter which the set-screws d d are tightened; or the compensation may be given byloosening only the one set-screw d and drawing a toward at by the bolt 9. Where "the pitman G is held on its eccentric a by a screw, h, the latter mode of adjusting is necessary.

The eccentric-lever F is journaled on the cupped screws 6 i, which i receive the pointed ends of thejournal j, which is adjustably. held in the lever F by the set-screw k, as shown.

The lever F is by the revolution of shaft E caused to oscillate, and gives motion at its foot to the forked shuttle-lever H, which, being journaled, oscillates to throw the shuttle in the cradle. The constant operation of lever H produces wear on its journal, for which I compensate-in the following manner:

I form on the bed or platform A the dependent boss I at a point to the rear of the journal of lever H. The boss I has a socket, l, 0

bored vertically in it, and a threaded opening, m, above it, in which screws a long screw, 12, which passes through the stud o of an L-shaped arm or bearing, 1), and holds it firmly up.

Lever His bored vertically to receive the pin q, whose upper end is pointed and journals in a recess in bed A, and whose lower end is rounded and rests in the cupped arm p.

Pin q is adjustable in the lever H by set-screw r passing through lever H. When the bearings of pin q wear out the set-screw r is loosened, pin q pushed up sufficiently, screw 4* tightened again, and then screw it is tightened, thus forcing the stud o of arm 12 upwardlyinto socket luntil all is steadyand true again, when screw r is tightened against stud 0.

The feed is regulated as follows: The feedbar 8 is hung at one end on a cross-pin in hearing t, and is given the proper up-and-down movement in the usual manner by the reciprocation ot a bent pitman, M, which passes through a hole in the feed-bar s and receives motion from the crank N on the shuttle-lever H, as shown. The back-andforth movement of the feed-bar .s' is given by the elbow-crank P, through one arm, a, of which passes the pitmau M, the other-arm, so, being connected to a lever operated by the pitman G, and the crank P itself being journaled on the bearing Q on the bed A. Arm w of crank P is usually oscillated by a lever whose other end is attached to the pitman G. such lever being pivoted at an intermediate fixed point, and the amount of oscillation has been governed by allowing the foot of pitman G to have more or less lost motion before striking up the lever, thereby producing an intermittent back-and-forth movement of the feed and requiring cushions and bumpers to subdue the noise. I connect this lever B at one end to the pitman G, and at the other to the arm to of crank P, by ball-joints m at, and provide a movable intermediate fulcrum whose position determines the amount of movement imparted to the feedbar s. The lever B is round and straight, and passes freely but closely through a sleeve, 3 whose outer surface is rounded ed, as shown. Sleeve 3 is held in the bracketz by the two pointed pivotscrews, 9, passing into bracket :2 laterally and horizontally. Bracket z slides accurately on the horizontal rod S, which is supported by the lugs T T, as shown. Bracket z is attached to the horizontal bar U, which passes through a guiding-slot in log T, and beyond that is attached to the slidin g head V, which is clamped by the thumbserew W, which moves in the long slot h. By this construction the pivotal point of lever B may be readily changed, and as its position makes the movement of the feedbar 8 long or short, it follows that the feed may be regulated with very great accuracy. By loosening the screw W the bar U may be easily moved in either direction, carrying with it the bracket 2 and its attached pivoted sleeve g, which slides upon the lever It, as stated.

I claim as my invention- 1. The combination of the two-part eccentric a a, having bevels b 1) adjustable with relation to each other, with the forked lever F, having theinner faces of forks f f beveled, as described.

2. The combination of the eccentric a, having bevel b, sleeve 0, and a suitable opening or socket, with eccentric at, having bevel b, sleeve 0, and stud e, bolt 9, shaft E, and set-screws d at, substantially as described.

3. The combination of lever F, pointed pin j, set-screw l5, cupped screws t i, and post B,

substantially as described.

4. The combination of bed A, having boss I, arm p, having stud 0 and cupped top, screw n, and set-screw r, with lever H, having pin 9, and sct-screw r, substantially as described.

5. The combination of lever B, sleeve 7 bracket 2, pivot-screws 9, rod S, lugs T T, bar U, head V, screw W, and slot h in bed A, substantially as described.

In testimony that I claim the foregoing as my own I have hereto afiixed my signature in presence of two witnesses.

THOMAS B. ROBERTS.

Witnesses:

T. J. MCTIGHE, T. J. PATTERSON, 

